1. Field of the Invention
The present invention relates to a soldering apparatus which performs soldering by jetting out streams of molten solder accumulated in a solder bath and permitting solder to come in contact with a piece to be soldered.
2. Description of the Related Art
There are various types of soldering apparatuses. FIG. 1 shows an example of an apparatus using a jet stream nozzle 12 of the fillet up nozzle type disposed in a solder bath 3.
The structure of the principal section around the fillet up nozzles (12a and 12b) of the soldering apparatus 1a is made up of the solder bath 3 accumulating solder 7, heating means 13 for the solder 7, a jet-stream nozzle 12a of the primary side disposed in the solder bath 3, and a jet-stream nozzle 12b of the secondary side of the fillet up nozzle type or the like, as illustrated. Note that a conveyor 5a slanted upward in the direction of travel is provided above the jet-stream nozzle 12a of the primary side and the jet-stream nozzle 12b of the secondary side, a mounted substrate 4 to be soldered being attached to this conveyor 5a. 
FIG. 2 schematically shows the jet-streaming condition of solder from the secondary side jet-stream nozzle 12b of the type presented in FIG. 1. This secondary side jet-stream nozzle 12b consists essentially of a front former 14 and a rear former 15, with the solder in the solder bath 3 of FIG. 1 being sent to between the front former 14 and the rear former 15 by a pump or a similar device not illustrated herein, and the solder thus sent being separated by the front former 14 and the rear former 15 into the direction reverse to the direction of travel of the conveyor 5a and into the direction positive thereto, as shown above.
Solder streams 16 and 17 separated before and after this process run into contact point A and contact point B relative to the mounted substrate 4 and flow out. The point A and the point B are called the peel back points of the solder stream, and, the length between A and B is called the DIP length, over which the solder 7 migrates and settles on the electrodes of the mounted substrate 4 and solder land, whereby the soldering process is implemented.
As described above, as to improve the soldering quality of the mounted substrate 4, it is necessary to control various conditions at each section of the soldering apparatus such as a conveying speed of the conveyor 5a proper for the type of solder, a temperature of the solder bath 3, a flux specific gravity, a preheater temperature, and a post-soldering cooling condition, all at optimum levels. Above all, most critical conditions include a flow speed, waveform, and wave amplitude of the jet stream of the solder.
Since the flow speed, the waveform, and the wave amplitude of the jet stream of the solder from the jet-stream nozzle vary with small variations in height, position and the like of the front former 14 and the rear former 15, it becomes necessary to optimize position, angle , etc. of the front former 14 and the rear former 15 by taking into consideration such factors as the condition at each portion of the apparatus at a given moment and the soldering conditions of the mounted substrate.
However, inasmuch as the prior art adjustments of the front and rear formers 14 and 15 of the jet-stream nozzles 12a and 12b are manually performed by using nuts and screws, conventional practice has been for the skilled worker to adjust the position and angle of each portion of the nozzle to the optimum levels while visually checking the finish status of the soldering results.
Consequently, the practice of manually adjusting the nozzles has made making micro-adjustments an extremely arduous task, resulting in problems of disparate soldering quality, low product yield, and low productivity.
Another problem is that it is impossible to perform timely controlling while moving the mounted substrate, so that application of optimum soldering conditions requires time. There is a further complication in that reproduction of the optimum soldering conditions is not an easy matter when a machine change is made.
Likewise, in the case in which the above-mentioned soldering apparatus is installed in production facilities spread across many areas of the country, the quality of soldering deteriorates in a particular facility in an area where skilled workers are hard to find, thus creating a situation where it is difficult to assure stable productivity throughout all related production facilities.
Moreover, in recent years, environmental problems have given rise to a demand for switching to lead-free soldering, thereby bringing about prospects of different soldering conditions than those thus far known in regard to the flux used, soldering properties and other factors, narrower margin of optimum soldering conditions than before, and difficulty of performing good soldering, wherefore it is considered likely that the problems enumerated above may become a reality to make the maintenance and control of soldering quality more and more difficult.
The present invention is directed to solving these problems, and it is preferable to provide a soldering apparatus which can perform timely micro-adjustments of the jet-stream nozzle in a short period of time with good accuracy, which contributes to improving the quality of soldering, improving workability, and improving operating efficiency, which can be operated and controlled by an operator with a relatively low degree of proficiency, and which can smoothly cope with any change in the apparatus.
According to an embodiment of the present invention, a soldering apparatus is provided, which can perform timely control of the optimum soldering conditions and do so from a remote place, and from which an improved quality of soldering can be obtained even by an operator with a relatively low degree of proficiency.
The soldering apparatus of the present invention is a soldering apparatus which operates to let molten solder accumulated in the solder bath to jet out a stream for soldering a piece to be soldered while the piece is conveyed in a predetermined direction, the apparatus including a jet-stream nozzle jetting out streams of molten solder in the solder bath, and having an end that can turn, drive means for driving a relative position of the end of the jet-stream nozzle to a predetermined position relative to the piece to be soldered, and control means for outputting the control signal to the drive means according to such predetermined position.
The jet-stream nozzle with the end is composed of a front former disposed at the end of the nozzle body on the upstream side of the conveying direction of the piece to be soldered and a rear former disposed at the end of the nozzle body on the downstream side of the conveying direction of the piece to be soldered, at least one of either the front former or the rear former being set up in such a way so as to be moved by the drive means receiving the control signal.
The drive means has a first drive means for driving the front former so that the front former is in a predetermined position and angle relative to the piece to be soldered.
The drive means is also made up of a second drive means for driving the rear former so that the rear former is in a predetermined position and angle relative to the piece to be soldered.
The soldering apparatus of the present invention further includes an image capture means for acquiring images of the jet-streaming condition of molten solder from the jet-stream nozzle and display means for displaying a condition of the jet-streaming of the molten solder, images of which are captured by the image capture means.
The control means stores other soldering conditions, together with the position of the end of the jet-stream nozzle relative to the piece to be soldered for each piece to be soldered.
The soldering apparatus of the present invention further includes second control means connected to the first control means via a communication line, the second control means outputting to the control means control signals for controlling via the communication line so that at least the end of the jet-stream nozzle is in a predetermined position relative to the piece to be soldered.
The second control means stores other soldering conditions, together with the position of the end of the jet-stream nozzle relative to the piece to be soldered for each piece to be soldered.
The soldering apparatus of the present invention further comprises second control means connected to the control means and the image capture means via a communication line and second display means for displaying acquired images inputted via the communication line from the image capture means, the second control means outputting to the control means control signals for controlling via the communication line so that at least the end of the jet-stream nozzle is in a predetermined position relative to the piece to be soldered.
The second control means stores other soldering conditions, together with the position of the end of the jet-stream nozzle relative to the piece to be soldered for each piece to be soldered.
The front former having a front support shaft supported by the nozzle body is provided so as to turn relative to the front support shaft.
The first drive means includes a pressure rod that can be driven vertically, the front former having a U-shaped member provided so as to turn relative to the front support shaft serving as a pivot, the end of the U-shaped member being supported by the pressure rod.
The rear former having a rear support shaft supported by the nozzle body is provided so as to turn relative to the rear support shaft.
The second drive means has a pressure rod drivable vertically, one end of the rear former provided so as to turn relative to the rear support shaft serving as a pivot, the other end being supported by the pressure rod.
The front former is provided so as to turn relative to the support shaft, while the first drive means is provided with both ends thereof moving vertically with an intermediate point as a fulcrum, including a first drive mechanism which, with its one end being linked to a first lever-shaped member holding up the front former and to one end of the first lever-shaped member, moves the one end of the first lever-shaped member vertically.
The first drive mechanism has a first motor and a first ascent and descent member with its one end screwed onto the shaft of the first motor and its other end linked to the lever-shaped member, which performs the ascent and descent movement corresponding to the number of revolutions of the first motor.
The rear former is provided so as to be able to turn relative to the support shaft, while the second drive means is provided with both ends thereof moving vertically with an intermediate point as a fulcrum, comprising a second drive mechanism which, with its one end being linked to a second lever-shaped member bearing the rear former and to one end of the second lever-shaped member, moves the one end of the second lever-shaped member vertically.
The second drive mechanism is made up of a second motor and a second ascent and descent member with its one end screwed onto the shaft of the second motor and its other end linked to the second lever-shaped member, which performs ascent and descent movement corresponding to the number of revolutions of the second motor.
The soldering apparatus of the present invention also has a flux supply means for supplying flux to the piece to be soldered that is positioned further on the side in the conveying direction of the piece to be soldered than the solder bath.
The soldering apparatus of the present invention additionally has a preheating means, disposed in between the flux supply means and the solder bath, for preheating the piece to be soldered that is coated with the flux.
Furthermore, in order to accomplish the objects described above, the solder apparatus of the present invention is a solder apparatus which applies solder to the piece to be soldered being conveyed in the predetermined direction by causing molten solder accumulated in the solder bath to jet out in stream, the apparatus comprising a primary jet-stream nozzle which jets out streams of molten solder in the solder bath and a secondary jet-stream nozzle which is disposed further downstream in the conveying direction of said piece to be soldered than the primary jet-stream nozzle, jetting out streams of molten solder in the solder bath and having a end that can be turned, drive means for driving so that the relative position of the end of the secondary jet-stream nozzle to the piece to be soldered may be in the predetermined condition, and control means for outputting the control signal corresponding to the predetermined condition to the drive means.
In the aforementioned soldering apparatus of the present invention, the soldering process is conducted as the molten solder in the solder bath is jetted out in a stream by the jet-stream nozzle with the end that can be turned so as to permit the piece to be soldered to come in contact with the molten solder.
Then, if it is desired to change the jet streaming condition of the molten solder from the jet-stream nozzles, the control signal corresponding to the relative position of the end of a nozzle that is desired to be varied is outputted by the control means to the drive means.
By virtue of the drive means, to which the control signal is inputted, the end of the jet-stream nozzle is driven so as to be in a position corresponding to the control signal.
Since, in this manner, adjustments of the position of the end of the jet-stream nozzle can be performed not manually but by using the control means and the drive means, timely micro-adjustments can be accomplished easily and the relative position of the end of the jet-stream nozzle can be varied in a short time with good accuracy.
In addition, storing in the control means other soldering conditions, together with the relative position of the end of the jet-stream nozzle to the piece to be soldered for each piece to be soldered makes it possible to reproduce at any time the soldering conditions that have been stored.
Further, by capturing images of the jet-streaming condition of the molten solder from the jet-stream nozzle through the image capture means, and by displaying the jet-streaming condition of the molten solder through the display means, it is possible to observe the jet-streaming condition of the molten solder, enabling the images acquired to be fed back to the soldering conditions in a timely manner.
Moreover, through the secondary control means connected via the communication line to the control means, the control signal controlling at least the positional status of the end of the jet-stream nozzle is outputted via the communication line and through the control means in receipt thereof, the control signal corresponding to such positional status is outputted to the drive means, whereupon through the drive means, the end of the jet-stream nozzle is driven so as to be in the relative position corresponding to the control signal.
As a result, remote operation of the jet-stream nozzle can be performed.